Cycloionone (CAS 5552-30-7) — Woody Middle to base Note Fragrance Ingredient
Cycloionone
CAS 5552-30-7
What Is Cycloionone?
Cycloionone is a synthetic fragrance compound often found in modern perfumes and body care products. It contributes to fresh, woody, and slightly floral scent profiles. This versatile ingredient helps create long-lasting fragrance compositions, making it valuable for perfumers seeking stable and diffusive notes in their formulations.
Safety Profile
GENERALLY SAFEWhat Does Cycloionone Smell Like?
Cycloionone opens with a crisp, airy freshness reminiscent of morning dew on cedar planks. As it evolves, the heart reveals a subtle floralcy akin to violet petals dusted with powdered sugar. The dry-down settles into a smooth, woody-amber embrace with remarkable tenacity, leaving a trail that’s simultaneously clean and sophisticated. Its unique character bridges aquatic freshness with warm base notes, making it a versatile performer in modern fragrance architectures.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a woody-amber diffuser to extend the citrus top notes and create the fragrance’s iconic ‘sun-warmed skin’ dry-down.
Provides the synthetic ambery backbone that enhances the fragrance’s modern freshness and projection.
2D Molecular Structure
SMILES: CC1=CC=C2C(C)(C)CCCC2(C)O1
Chemistry, Properties & Perfumer Guide
The Chemistry
Cycloionone belongs to the cyclic ketones class, structurally related to ionones but with enhanced stability. While not found in nature, it shares olfactory characteristics with some naturally occurring woody-amber molecules. Industrial synthesis typically involves aldol condensation pathways followed by cyclization. The absence of chiral centers makes it easier to produce consistently compared to many natural isolates.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Odor Threshold | 0.01 ppm in air |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | Up to 5% | For woody-amber diffusion |
| Body Care | 0.5-1.5% | Up to 2% | Provides long-lasting freshness |
Classic Accords
Tip: Use with ionones to create a seamless floral-woody transition in heart notes.
Alternatives & Comparisons
When seeking more pronounced woody character with less sweetness. Iso E Super has higher tenacity but less floralcy.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No current IFRA restrictions. Listed as safe up to 10% in finished products (IFRA 49th Amendment).
RIFM Assessment
RIFM evaluation completed in 2018 with no significant safety concerns at typical usage levels.
Sustainability
As a synthetic material, cycloionone production avoids natural resource depletion. Modern manufacturing processes have reduced solvent waste and energy consumption compared to early synthetic routes. Being petroleum-derived, its carbon footprint is offset by requiring minimal quantities per formulation due to high potency.
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References
- IFRA Standards Library (2021). 49th Amendment. IFRA Official
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID20863558
Physical Properties
| Molecular Weight | 192.302 g/mol🔬 EPA CompTox |
| Density | 0.952 g/cm^3📊 OPERA |
| Boiling Point | 240 °C🔬 EPA CTX |
| Melting Point | 38.648 °C📊 OPERA |
| Flash Point | 106.833 °C📊 OPERA |
| Refractive Index | 1.507 Dimensionless📊 OPERA |
| Molar Volume | 199.179 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.527 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.527 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.527 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.07 Log10 unitless📊 OPERA |
| Water Solubility | 0.005 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.134 mmHg📊 OPERA |
| Viscosity | 3.837 cP📊 OPERA |
| Surface Tension | 30.196 dyn/cm📊 OPERA |
| Thermal Conductivity | 117.465 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 9.23 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 0 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 59.27 cm^3/mol📊 OPERA |
| Polarizability | 23.497 Å^3📊 OPERA |
Data Sources:
🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.
